The present invention relates to a drive transmission means which is attached to a developing unit of an image forming apparatus.
Generally, the developing unit of an electrophotographic image forming apparatus is composed of: a developing unit main body which forms a housing; a first stirring member which stirs toner supplied into the developing unit; a second stirring member which is rotated in the opposite direction to the first stirring member; a supply roller which supplies to a developing sleeve a two component developer in which toner and carrier are fully stirred and mixed by the first and second stirring members; the developing sleeve; a developer thin layer forming means; and a drive transmission mechanism. An electrostatic latent image which is formed on the surface of a photoreceptor adjoining the developing sleeve with a predetermined gap, is given toner conveyed by the developing sleeve so that a toner image can be developed. Rotation of the stirring members, the supply roller and the developing sleeve is transmitted by the drive transmission mechanism section which is attached to a side surface of the developing unit main body.
Conventionally, for example, each stirring member and the supply roller are rotatably supported by bearing sections provided on both side portions in the longitudinal direction of the developing unit main body which forms a housing of the developing unit, and connected with the drive transmission means attached to one side portion of the developing unit main body so that rotation of a drive source can be transmitted.
As described above, when bearing sections of each stirring member and the supply roller are provided on both side portions of the developing unit main body, assembling the stirring members and the supply roller with respect to the developing unit main body is not simple, so that assembly is troublesome.
Further, conventionally, when the developing unit is assembled, the stirring members and the supply roller which are mounted in the developing unit, and the drive transmission member of the drive transmission mechanism are connected so that their mechanical phases match each other, for example.